Piston-ring-grinding apparatus



NOV- 12, 1929; w OLSON 1,735,333

PISTON RING GRINDING APPARATUS Filed Aug. 10. 1928 2 Sheets-Sheet l l /7 v wuanto'a Gearga ZZZ 71501:

NOV. 12, 1929. a w, OLSON 1,735,333

A PISTON RING GR INDING APPARATUS Fil ug- 10. 1928 2 Sheeflt.sSheef 2 Esarga [71 01.52711 Patented Nov. 12, 1929 UNITED STATES PATENT? OFFICE GEORGE W. OLSON, 0F MUSKEGON, MICHIGAN, ASSIGNOR 'IO MUSKEGON PISTON RING COMPANY, OF MUSKEGON, MICHIGAN, A CORPORATION OF MICHIGAN PISTON-RING-GRINDING APPARATUS Application filed August 10, 1928. Serial No. 298,6'2'7.

The primary object of my invention, which relates to the grinding of concentric piston rings for internal combustion and other types of engines, pumps, air compressors and other devices wherein piston rings are used to insure tight joints with encircling cylinder walls is to provide means whereby, in comparison with the best of other known methods,

the production rate for such work may be greatly increased without widening of limits as to circular distortion or peripheral accuracy and concentricity or uniformity of ring thickness with correspondingly uniform distribution of resiliency as expressed by pressure against cylinder walls.

Another object of my invention is to provide means whereby eccentric or out-of-round piston ring castings may be trued up quickly and accurately by grinding under conditions such as tend not only to obviate distortion of the rings while being ground but to eliminate subsequent distortion due to the release of internal stresses set up by the grlnding process.

A further object of my invention is to provide a device readily attachable to and operable by grinding machines of different makes designed for grinding parts other than piston rings, any convenient source of power being susceptible of utilization for driving the moving parts of my device, which is particularly adapted for association with any grinding 1nstrumentality of a character suited to the kind and grade of work to be done in finish grinding the periphery of concentric piston rings.

An additional object of my invention is to provide means whereby more fully to realize the advantages of adjustability in yieldably supporting the work, in controlling the pressure of frictional driving contact that keeps the work moving, in regulating the pressure with which the work may be held without distortion against the grinding instrumentality, and in determining efiective grinding limit as expressed by thickness of the work when finished.

My invention is embodied or expressed an adjustably mounted work holder moved to and from the dressing or grinding instrumentality by manual or other actuation of a toggle lever for developing pressure for holding movable pieces of work firmly but without distorting them, combined with yieldable means for driving these movable pieces of work through frictional contact, means for preventing the work from moving lengthwise of the supporting mandrel while the face of the revolving dressing or grind ing wheel moves transversely across the work mounted on a supporting mandrel of smaller external diameter than the internal diameter of the circular pieces of work being ground, means for limiting the amount of grinding so as to control the thickness of the work when finished also being a distinguishing feature of my invention, as indicated by the following description and accompanying illustrations, of which Figure 1 is a plan or top view,

Fig. 2 an end elevation;

Fig. 3 an elevation looking towards the ring-driving friction rolls from the grinding wheel, while Fig. 4 is a conventional cross sectional view showing the operative relationships existing between the various elements of the device when running in production.

The same reference numbers apply to the following parts of all drawings:

1.Frame or base on which the piston-ringmandrel carriage 3 with appurtenant parts is slidably mounted for actuation through manipulation of toggle handle 13.

2.--Gear-'shaft-supporting guard or shield covering friction roll drive gears 17 and 18.

3.Sliding carriage for fixed and movable centers 8 and 9 by which piston-ring arbor or mandrel 15 is supported.

4.Adjustably mounted friction-rollersupport brackets tapped to receive vertically disposed right-and-left threaded adjusting screws 28 that serve, when turned, to force the friction rolls apart to release the ground piston rings or draw the rolls together to in crease their hearing pressure on the rings being ground.

5.Toggle-joint knuckle.

6.Toggle-joint link.

7.-Pressure plate for transferring toggle pressure to the arbor or mandrel 15 which menses On the so-called driving ends 23 of the Eriction rolls 26 are gears 17 that mesh with a similar pair of ears l7 driven by a pinion 18 on drive shatt 29, but any other equally eilective means of driving adjustably mounted friction rolls tor the purpose herein described could be employed without departing from the spirit or scope of my invention, the essence of which is expressed through the structure disclosed by the accompanying drawings, but not thereby specifically limited to the application represented.

Any suitable source of power may be utilized in driving shaft 29 and the train of ears that serve to turn the friction drive rolls which hold the rings firmly against the work-holding mandrel, as diagrammatically illustrated by Fig. 4, while driving them, rotation of the work being indeperdent of rotation of the dressing or grinding wheel whose rate, of travel with reference to the speed at which the work turns may be varied to suit whatever requirements may be imposed by the character of the material, speed of production, grade of finish desired, etc.

Upon turning. the adjusting screws 28 to bring the friction drive rolls 26 into driving contact with the rings 30, the latter are brought more firmly into contact with the mandrel 15, to which the toggle pressure is communicated through the link 6 and pres sure plate 7 to the carriage 3 having integral supports for the listed and movable centers 8 and 9 on which the work-carrying mandrel 15 is mounted. Movement of the carriage 3 towards the grinding wheel 33 under the actuating influence of the toggle brings the rings into contact with the grinding wheel, where they may be held under variable manual pressure while being moved transversely across the face of the wheel until the limit of carriage movement and therefore of grinding, as determined by setting of toggle eye-bolt adjusting nuts 22, is reached and rings are concentric or of uniform thickness and pe ripheral smoothness. The pressure plate 7 may readily be shitlted to accommodate rings of dil'l'erent cross sectional thickness by changing the position of the adjusting nuts 22 on toggle eye bolt 21 passing through the pressure plate, which slides on the slotted head guide pins 32.

Having tally disclosed the essence of my invention, 1 wish to be understood that t e physical embodiment thereof, as herein presented, is but one expression of its applica tion, structural details obviously be susceptible to vanation without lop. from its spirit as indicated by tne following claim What ll claim 1.. a grinding machine having movable worlr table transversely reciprocable witl'i r ference to a fixedly-mounts l grinding wheel rotating in plane at right to the axis of the mandrel on which the work to be dressed or ground is placed, a base or frame having slidably mounted thereon a carriage provided with fixed and adjustable centers for supporting a work-carrying mandrel movable (with carriage) to and from the grinding wheel, adjustably connected means for moving said carriage and mandrel so as to bring the work carried by the latter into contact with the grinding instrumentality, adjustable means for limiting said movement to control the thickness ot the finished work, adjustable means for driving work by frictional contact with two adjustably mounted rolls of yieldable material whose resiliency offsets or compensates for eccentricity and surface inequalities, means for varying the pressure with which the rolls are made to bear on the work and hold it to the work-supporting mandrel. while driving it but not great enough to distort the work, adjustable workguiding means for keeping the work in line with the endwise positioning ot the worlrholding mandrel, means for locking the adjust-able mandrel-supporting center in adjusted position, and means for rotating the adjustably-mounted work-driving friction rolls in association with the means employed for driving the grinding instrumentality and imparting to the worlr table reciprocating motion parallel with the axis of the grinding wheel.

2. In a machine for dressing or grinding the outer peripheries of a multiplicity of concentric piston rings or similar circular parts, adjustable means "for supporting the work so as to drive it by frictional contact with two adjustably mount-ed rolls oi? sutiiciently yieldable structure to oi'tset the distortion-producing effect of initial out-otroundness or peripheral surface inequalities of work, means for varying the friction driving pressure between said rolls and rings, means for actuating said adiustably mounted "irictioirdrive rolls in association with means for driving other parts oi the machine, the axes of said friction-drive rolls bong equidistant from and parallel to the line of conbetween the mandrel upon which the rings are placed for grinding and the inner peripheries of the rings, thus providing a three-point type of suspension which is favorable to rapid and ace grinding, the thickness to which the rings are ground being controlled through use of adjustabl nism for moving to and from the wheel the sliding carriage which holding mandrel. and snpportir are mounted.

3. in a finding machine having a work table "is with reference to a "I g u wheel, means for adjust-ably St por ting the worlr to be dressed or ground on 1 so mount on a sliding carria,

mandrel. as to be movable to liltl wards and away from the face of the grinding wheel, means for giving indicated movement to said sliding carriage, locking means for holding Work-mandrel adjustment, guiding means for holding work in line with endwise positioning of work-supporting mandrel, means for varying the contacting pressure with which a pair of friction-drive rolls of yieldable material are made to bear upon the work they both drive and hold in a manner favorable to accurate grinding, means for controlling ring thickness by limiting movement of the work supporting mandrel towards the grinding wheel, and means for driving the friction rolls in conjunction with means for actuating other elements of the machine.

4. In an adjustable fixture adapted for attachment to the movable table of a grinding machine for the purpose of dressing or finish ing the outer peripheries of a multiplicity of concentric piston rings or similar circular parts, the combination of adjustable worksupporting members forming part of a carriage slidable to and from the dressing or grinding instrumentality, an adjustable work-guiding member for holding the work to a position corresponding with that of the work-supporting mandrel on which the rings are mounted, adjustable work-driving members of yieldable material, an adjustable pressure-creating and work-support car-' riage-actuating member for holdin the work in contact with the dressing or grinding instrumentality' under pressure variable at will, with means for locking the setting or adjustment of work supporting members, means for actuating the work-driving members, means for varying the contacting pressure between the work and the work driving members, means constituting a feature of the grinding machine, for moving the work back and forth transversely across the face of the grinding wheel while in contact therewith, and means for controlling ring thickness by stop-limit setting of work-support-carriageactuating mechanism, substantially as described herein. i

In testimony whereof I afia my signature.

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